Process of dyeing cellulosic fibers with montmorillonite clay and a polymerized fatty nitrozen compound and products obtained thereby

ABSTRACT

Cellulosic fibers are dyed by treatment with an anionic dye, such as Nigrosine 02P or OPX, color index 5420, an alkali metal or acid montmorillonite clay such as bentonite, and a fatty nitrogen compound, prepared from polymerized fat acids, such as tallow diamine. Paper is prepared by adding the dye, clay and fatty amine or quaternary ammonium compound to the aqueous dispersion prior to the formation of sheets therefrom.

United States Patent General Mills, Inc.

[21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] PROCESS OF DYEING CELLULOSIC FIBERS WITH MONTMORILLONITE CLAY AND A POLYMERIZED FATTY NITROZEN COMPOUND AND PRODUCTS OBTAINED THEREBY 17 Claims, No Drawings [52] U.S.Cl 162/162, 8/7,8/84,162/179,162/181D,162/182,260/583 1 [51] lnt.Cl D2lh3/80 [50] Field of Search 162/179, 182, 162, 183, 181; 8/7, 84; 260/5831 [5 6] References Cited I UNITED STATES PATENTS 2,129,264 10/1938 Downing 8/84 X 2,492,702 12/1949 Neubert 162/164 3,281,470 10/1966 Vertnik 260/5831 2,658,828 9/1948 Pattilloch 162/182 2,694,633 1 1/1954 Pattilloch 162/182 2,730,446 l/l956 Hutchins 162/164 3,248,280 4/1966 Hyland 162/164 OTHER REFERENCES Kress, Study of Dyestuff Absorptionm, Tappi Paper Trade Journal, Vol. 1 l7.

Scherubel, Chem. Abstracts, Vol. 34 1940).

Casey, Pulp and Paper, Vol. 11, 2 nd Edition, pp. 745- 747 and pp. 1,012- 1,014.

Discrens, The Chemical Technology of Dyeing and Printing, 1951, pp. 333- 338 and pp. 44- 51.

Primary Examiner-S. Leon Bashore Assistant Examiner-Richard H. Anderson Attorneys-Anthony A. Juettner, William C. Babcock and Gene 0. Enockson PROCESS OF DYEING CELLULOSIC FIBERS WITH MONTMORILLONITE CLAY AND A POLYMERIZED FATTY NITROZEN COMPOUND AND PRODUCTS OBTAINED THEREBY The present invention relates to a process for dyeing cellu losic fibers and to the products obtained thereby. In one preferred embodiment, it particularly relates to the production of colored paper from cellulosic fibers wherein an anionic dye is used in combination with certain fatty nitrogen compounds and an alkali metal or acid montmorillonite clay.

Colored paper is commonly prepared by adding a dye to the paper while it is still in the fibrous state-i.e., prior to being formed on the machine. Such procedure is commonly referred to as "beater dyeing." The open top and vigorous mixing action of the beater makes it an excellent place to add the dyes. However, the term beater dyeing" is taken to include also dyeing in Hydropulpers, Dynopulpers, Jordans mixing chests, mixing tanks, fan pumps, head boxes and the like where similar mixing conditions exist.

The mainclasses of dyes used in the production of colored papers using beater dyeing are the acid, direct and basic dyes. The first two classes, namely the acid and direct dyes, are anionic in nature and are generally sodium salts of color acids. They are water soluble and are available in practically all shades of the rainbow. The acid dyes have little, if any, afiinity for cellulose. Accordingly, they have most commonly been employed where the furnish also contains alum or both rosin and alum.

l have now discovered that the retention of anionic dyes by cellulosic fibers can be improved if the fibers are treated with a combination of the anionic dye, certain fatty nitrogen compounds and an alkali metal or acid montmorillonite clay. I do not fully understand the invention. In this respect, the use of the anionic dye in combination with the montmorillonite clay alone yields handsheets which are generally not dyed to any appreciable extent. Also, various of the fatty nitrogen compounds are completely ineffective in improving the retention of the anionic dyes by the cellulosic fibers. Yet when these same fatty nitrogen compounds are used in combination with the montmorillonite clay, substantial retention of the anionic dyes by the fibers is obtained. And when the clay is used in combination with fatty nitrogen compounds which have some effectiveness, retention of the anionic dyes is increased over the use of said nitrogen compounds alone, It can only be theorized that the clay and fatty nitrogen compounds form some type of complex which is capable of being retained by the fibers. Such complex is then apparently able to react with and thus retain appreciable amounts of the anionic dyes.

My process has particular application to the dyeing of cellulosic fibers with acid dyes. However, it is also of value when other anionic dyes such as the direct dyes are to be used. While these latter materials have affinity for cellulosic fibers, the dyeing intensity can be increased with the use of the montmorillonite clay-fatty nitrogen compound combination and the amount of the direct dyes needed to produce a certain color may be reduced. My process is especially valuable in dyeing the cellulosic fibers prior to their formation into sheets although it is also useful in dyeing already formed sheets of paper as well as fabrics and the like derived from cellulosic fibers such as cotton.

As indicated, the anionic dye, alkali metal or acid montmorillonite clay and fatty nitrogen compound are preferably added to dilute dispersions of the cellulosic fibers prior to the formation of sheets from such dispersions. Preferably, the addition is made to the beater or refiner or the the already beaten or refined fibers. In the latter case the dye, clay and fatty nitrogen compound are thoroughly mixed with the beaten or refined fibers. Any of the wide variety of commercially available beaters and or refiners can be used. The cellulosic fibers can be any of those used in papermaking, such as those commonly referred to as sulfite, soda, sulfate and ground wood stock or fibers derived from rag, cotton, bast, flax and stem fibers such as straw, or from repulped broke.

The fibers may be bleached or unbleached. The concentration of the fibers in the aqueous dispersion is generally less than about 4.0 percent by weight and preferably in the range of 0.5 to 3.0 percent by weight.

The fatty nitrogen compounds useful in the present invention are fatty amines and quatemaries derived from fat acids and polymeric fat acids. The preferred fatty amines are those having the following formulas H[-I I-GH D-CH1]zNH,

where p is an integer of l or 2, n is an integer of 2 to about 4, m is an integer of 3 or 4, x is an integer of 2 to about 40 or higher, R is an aliphatic hydrocarbon radical of eight to 22 carbon atoms, R and R are hydrogen or aliphatic hydrocarbon radicals of eight to 22 carbon atoms, R is the polyvalent hydrocarbon radical of a polymeric fat acid and D is the divalent hydrocarbon radical of a dimerized fat acid.

The preferred fat acid based quatemaries are those having where p, n, m, x, R, R and D are as defined above, X is a quaternary ammonium anion, R is an alkyl group of one to about six carbon atoms or the benzyl radical or an aliphatic hydrocarbon substituted benzyl radical wherein the aliphatic substituent contains from one to about six carbon atoms and R and R are aliphatic hydrocarbon radicals of one to 22 carbon atoms.

Various of the amines of the formula (I) are commercially available. Illustrative of such compounds are octyl amine, lauryl amine, myristyl amine, palmityl amine, stearyl amine, oleyl amine, linoleyl amine, palmitylmethyl amine, stearylmethyl amine, oleylmethyl amine, diluaryl amine, dimyristyl amine, dipalmityl amine, distearyl amine, dioleyl amine, dilinoleyl amine, trilauryl amine, trioctyl amine, dilaurylmethyl amine, distearylmethyl amine and the like. The long chain aliphatic hydrocarbon radicals may be alike or different, straight or branched chain and saturated or unsaturated. As a general matter, many of these amines are derived from mixtures of fatty acids obtained from fatty oils so that the groups will be of varying lengths. These mixed acids may be obtained from various animal and vegetable oils. Furthennore, the amines may be derived from acids other than those obtained from animal and vegetable oils--i.e., acids ultimately obtained from olefin polymers, from "Oxo" products, and Claisen condensation produces. However, due to the length of the long chain aliphatic group or groups such amines are also considered as fat acid amines.

Amines of the formula (II) are also commercially available and can be prepared in the conventional manner. Thus a primary or secondary amine as above described can be condensed with an a,/3-unsaturated nitrile, such as acrylonitrile, crotonitrile and methacrylonitrile, and the resulting condensation product or adduct can be catalytically reduced to yield the amine.

The amines of the formulas (lll), (IV) and (V) are derived from polymeric fat acids. Such polymerized fat acids are prepared by polymerizing ethylenically unsaturated monobasic carboxylic acids having 16 to 22 carbon atoms or the lower alkyl esters thereof. The preferred aliphatic acids are the mono and polyolefinically unsaturated 18 carbon atom acids. Representative octadecenoic acids are 4-octadecenoic, 5-octadecenoic, o-octadecenoic (petroselinic), 7-octadecenoic, 8-octadecenoic, cis-9-octadecenoic (oleic), trans-9octadecenoic (elaidic), l1(vaccenic), l2-octadecenoic and the like. Representative -octadecadienoic acids are 9,12-octadecadienoic (linoleic), 9,1 l octadecadienoic, l0,l2-octadecadienoic, 12,15-octadecadienoic and the like. Representative octadecatrienoic acids are 9,l2,l5-octadecatrienoic (linolenic) 6,9,1 2-octadecatrienoic, 9,1 l, l 3-octadecatrienoic (eleostearic), l0,12,14-octadecatrienoic (pseudo-eleosterric) and the like. A representative 18 carbon atom acid having more than three double bonds is moroctic acid which is indicated to be 4,8,12, l 5-octadecatetraienoic acid. Representative of the less preferred (not as readily available commercially) acids are: 7-hexadecenoic, 9-hexadecenoic (palmitoleic), 9-eicosenoic (gadoleic), l l-eicosenoic, 6,10,14-hexadecatrienoic (hiragonic 4,8, l 2, l 6-eicosatetraenoic, 4,8,12,15 ,1 8-eicosapentanoic timnodonic I 3-docosenoic (erucic), l l-docosenoic (cetoleic), and the like.

The ethylenically unsaturated acids can be polymerized using known catalytic or noncatalytic polymerization techniques. With the use of heat alone, the mono-olefinic acids (or the esters thereof) are polymerized at a very slow rate while the polyolelinic acids (or the esters thereof) are polymerized at a reasonable rate. If the double bonds of the polyolefinic acids are in conjugated positions; the polymerization is more rapid than when they are in the nonconjugated positions. Clay catalysts are commonly used to accelerate the dimerization of the unsaturated acids. Lower temperatures are generally used when a catalyst is employed.

The polymerization of the described ethylenically unsatu rated acids yields relatively complex products which usually contain a predominant portion of dimerized acids, a smaller quantity of trimerized and higher polymeric acids and some residual monomers. The dimerized acids having 32 to 44 carbon atoms can be obtained in reasonably high purity from the polymerization products by vacuum distillation at low pressures, solvent extraction or other known separation procedures. The polymerization product varies somewhat depending on the starting fat acid or mixture thereof and the polymerization technique employed-- i.e., thermal, catalytic, particular catalyst, conditions of pressure, temperature etc. Likewise, the nature of the dimerized acids separated from the polymerization product also depends somewhat on these factors although such acids are functionally similar.

Analysis of dimerized acids prepared from linoleic acid rich starting materials using heat alone or heat plus a catalyst, such as an acid or alkaline clay, shows that the product contains structurally similar acids having monocyclic tetrasubstituted ring structures as well as acids with two and three rings, such additional rings generally being fused to the six carbon atom ring. The clay catalyzed dimerized acids have been shown to contain some aromatic rings according to ultraviolet and infrared spectroscopy. These aromatic rings are believed to be formed by hydrogen transfer (by catalytic action of clay) from a substituted cyclohexene ring to form a substituted benzene ring. Polymerization of pure oleic acid using a clay catalyst has been shown to yield a mixture of dimerized fat acids of which approximately 25-30 percent by weight have a one ring cyclic structure with the remainder being noncyclic. However, when mixtures of oleic and linoleic acids (such as from tall oil) are polymerized, the resulting dimerized fat acid contains little if any dimer having a noncyclic structure.

lt is apparent from the above and other published analyses that the polymerization of the ethylenically unsaturated acids yields complex products. The dimer fraction thereof, generally consisting of a mixture of acids, can be assigned the formula:

HOOC-D-COOH where D is a divalent hydrocarbon group containing 30 to 42 carbon atoms; It is also apparent that said divalent hydrocarbon group is complex since a mixture of acids normally results from the polymerization and subsequent fractionation. These acids have structural and functional similarities. Thus such mixture of acids contains a significant proportion of acids having a six carbon atom ring (about 25 percent or more even when the starting fat acid is a mono-olefinically unsaturated acid such as oleic). The remaining carbon atoms in the divalent hydrocarbon group of such ring containing acids are then divided between divalent and monovalent radicals which may be saturated or ethylenically unsaturated. Such radicals may form one or more additional cyclic structures which are generally fused to the first six membered ring. Many of such dimeric acids may be considered as having a theoretical idealized, general formula as follows:

R RC 0 OH where R' and R" are divalent hydrocarbon radicals, R and R"" are monovalent hydrocarbon radicals and the sum of the carbon atoms in R'-R"" is 24-36. The ring may be saturated or it may contain one to three double bonds depending on the specific starting material, polymerization conditions and subsequent treatment including hydrogenation. It is also understood that the R'R" radicals may form one or more additional cyclic structures which are generally fused to the first ring.

As a practical matter, the dimeric fat acids are preferably prepared by the polymerization of mixtures of acids (or the simple aliphatic alcohol esters--i.e., the methyl esters) derived from the naturally occurring drying and semidrying oils or similar materials. Suitable drying or semidrying oils include soybean, linseed, tung, perilla, oiticia, cottonseed, corn, sunflower, dehydrated castor oil and the like. Also, the most readily available acid is linoleic or mixtures of the same with oleic, linoleic and the like. Thus it is preferred to use as the starting materials, mixtures which are rich in linoleic acid. An especially preferred material is the mixture of acids obtained from tail oil which mixture is composed of approximately 40-45 percent linoleic and 50-55 percent oleic. It is also preferred to carry out the polymerization in the presence of clay. Partial analysis of a relatively pure dimer fraction (98.5 percent dimer) obtained from the product prepared by polymerizing the tall oil fatty acids in the presence of 10 percent by weight of an alkaline montmorillonite clay at a temperature of 230 C. and a pressure of p.s.i. for 5 hours showed that it was a mixture of C acids the major proportion thereof being monocyclic of the above general formula with a substantial amount of the acids having a ring containing three double bonds (aromatic) and saturated side chains, Such mixture of acids was used in the preparation of the dinitrile and thence the diamine used in the example to follow. It is also to be understood that the corresponding hydrogenated polymeric fat acids are useful in preparing the polynitriles and thence the polyamines and quaternaries employed in the present invention.

The polymerized fat acids are converted to the corresponding polynitriles by reaction with ammonia under nitrile forming conditions. The details of this reaction are set forth in Chapter 2 of Fatty Acids and Their Derivatives" by A. W. Ralston, John Wiley & Sons, lnc., New York (1948).

The polyamines of the formula (111) above are then prepared by hydrogenating the polynitriles in the presence of ammonia. Polyamines of this type are commercially available materials. Their preparation is further described in McCaleb et al. Pat. No. 3,010,782 which disclosure is incorporated herein by reference.

Polyamines of the formula (IV) are also commercially available. Such polyamines are prepared by reacting the compounds of formula (11]) with an a,B-unsaturated nitrile such as acrylonitrile, crotononitrile, and methacrylonitrile and then catalytically reducing the resulting polynitrile. The preparation of these compounds is also further described in the aboveidentified McCaleb et al. Patent and in Sveum et a1. Pat. No. 3,299,138, which disclosure is also incorporated herein by reference.

The polyamines of the formula (V) are prepared by the condensation polymerization of the dinitriles under secondaryamine-forming conditions. Typical reaction conditions utilize hydrogen pressures in the range of 25 to 1000 p.s.i.g. at temperatures in the range of 200 to 290 C. The preparative reaction is illustrated by the following equation:

The ammonia byproduct is swept from the reaction mixture with hydrogen gas. Various of these polyamines are also commercially available and their preparation is further described in Vertnik Pat. No. 3,217,028 which disclosure is incorporated herein by reference.

Various of the described amines and polyamines are converted to the quaternary ammonium compounds also useful in the present invention by reaction with various quaternary saltforming substances by well known and conventional procedures. The quaternary salt-forming compounds include methyl chloride, methyl bromide, methyl iodide, ethyl chloride, ethyl bromide, ethyl iodide, n-propyl chloride, npropyl bromide, isopropyl bromide, n-butyl chloride, n-butyl bromide, isobutyl bromide, n-hexyl chloride, benzyl chloride, benzyl bromide, methyl sulfate, ethyl sulfate, methylbenzene sulfonate, methyl p-toluenesulfonate and the like. The saltforming substances are preferably the alkyl halides and especially the alkyl chlorides such as methyl chloride. The quaternary reaction can be carried out in the presence of a solvent such as an alcohol--i.e., isopropyl and butyl alcohols. The reaction is also advantageously carried out in the presence of a base, such as the alkali metal hydroxides, alkaline earth hydroxides, alkali metal carbonates, alkali metal alkoxides and the like. Such bases serve to take up any acid liberated in the quaternization reaction.

The preparation of various of the quaternary ammonium compounds useful in the present invention is further described in the above-identified Sveum et al. Pat., Nordgren et al. Pat. No. 3,235,596, and Swanson lPat. No. 3,131, 998, the disclosures of which are incorporated herein by reference. Any of the alkali metal montmorillonite clays can be used but the sodium clays are preferred over the lithium and potassium clays for example. It is also to be understood that the alkali metal montmorillonites occur naturally in an impure form, that is they are mixed with other clay materials. Such mixtures containing substantial amounts of the montmorillonite clays are suitable in the practice of the invention and are included in the term alkali metal montmorillonite clay. Of course, the al-.

kali metal montmorillonites can be used in various purified forms if desired. The acid (or hydrogen) clays are easily obtained by passing an aqueous suspension of the alkali metal clays through a column containing the hydrogen form of a cation exchange resin.

Any of a wide variety of anionic dyes can be used in the present invention. Typical of such dyes are the following acid dyes: Nigrosine O21, Nigrosine OPX Dustless, Nigrosine J, Acid Blue R, Acid Blue B, Acid Blue 2R, Acid Blue 3B, Acid Blue 26, Quinizol Blue BP, Bond Blue B Conc., Acid Green 2G Conc. Dustless, Acid Orange Y Dustless, Acid Green Extra Conc., Acid Orange RR Dustless, Azo Scarlet Y Extra Conc., Crocein Scarlet MOO Conc. Dustless, Crocein Scarlet MOON, Serisine B, Fast Red Conc. Acid Carminette, Fast Acid Carminette SC, Metanil Yellow MXXX Conc. Dustless, Acid Violet 4BNS Dustless, Acid Violet 6B Conc., Chinoline Yellow W Conc. and the like. These and other acid and direct dyes are disclosed in Dyestufi Data For Paper Makers," American Cyanamid Company 1952, pp. 17 -21 and 25-30 and in University of Maine Lectures On Pulp and Paper Manufacture, 1950, pp. 241 -245, the disclosures of which are incorporated herein by reference.

The amount of dye added to the cellulosic fiber is not critical and, of course, depends on the strength of the dye and paper color desired. Preferably the dye is used in an amount of about 0.05 to 1.0 percent by weight based on the dry weight of the fibers.

The fatty nitrogen compound and the alkali metal or acid montmorillonite clay are used in an amount sufficient to increase the retention of the anionic dyes by the fibers. Of course, the said clay is used in an amount to increase the effectiveness or render the fatty nitrogen compound effective. In preferred terms, the clay is used in an amount of about 0.05 to 1.0 percent weight and the fatty nitrogen compound in an amount of about 0.05 to 1.0 percent by weight, such percentages being based on the dry weight of the fibers.

The anionic dye is preferably added to the fibers in the form of a dilute aqueous solution or dispersion. Likewise, the fatty nitrogen compound and clay are also preferably added in the form of dilute aqueous solutions or dispersions. Where the fatty nitrogen compound is an amine, it can be solubilized by at least partially neutralizing the same with a water soluble organic or inorganic acid such as acetic acid and mineral acids including hydrochloric, sulfuric and the like. The use of dilute solutions or dispersions of dye, clay, and fatty nitrogen compound results in a more even distribution thereof on the fibers. It is also preferred that the said solutions or dispersions contain less than abut 10 percent by weight of the dye, clay and/or fatty nitrogen compound. In many instances it is preferred that the alkali metal or acid montmorillonite clay is first added to the fibers followed by addition of the fatty nitrogen compound and then the anionic dye. Where the materials are added to already formed sheets or fabrics derived from cellulosic fibers, the clay dispersion is also first preferably applied. In paper making, such addition can take place at the calender. But generally any method of dipping, spraying etc. of the sheets or fabrics can be employed.

In the preferred procedure wherein the anionic dye, fatty nitrogen compound and alkali metal or acid montmorillonite clay are thoroughly mixed with an aqueous pulp or fiber dispersion, sheets can then be prepared using conventional techniques. In this respect, the relatively uniform dispersion of the pulp fibers containing the dye, fatty nitrogen compound and clay is filtered through a screen which leaves a wet sheet on the screen. This sheet can then be dried and otherwise processed to make paper which can be used for a variety of purposes including use as a nonwoven fabric. Any of the commercially available forming machines can be used including the Fourdrinier and cylinder machines. The wet sheets are preferably dried at temperatures of 200 V. to 250 V. to a moisture content of less than about 10 percent. Any conventional drying technique can be used such as steam heated dryers.

It is also to be understood that conventional additives such as fillers and the like can be added. Representative fillers are talc, CaCO silica, TiO and so forth.

The following examples further illustrate and describe the process and products of the present invention and are not to be considered as limiting. Unless otherwise indicated, all parts and %'s are by weight.

EXAMPLE 1 One litersamples of an aqueous dispersion'of moderately II RN- CIhCHzCITr-NH; 10 where R is the mixed C C and C carbon atom alkyl radical derived from the corresponding fraction of fatty acids obtained from tallow (the solution was prepared by adding I cc. diamine per I cc. H O, the H 0 containing HCl at a concenl 5 tration of l cc./500 cc. H 0); and 1 percent suspension of degritted oil well grade Wyoming bentonite (the bentonite was degritted by centrifuing an approximate 5 percent slurry of bentonite to remove nonbentonite material and the supernatant was diluted to 1 percent solids with water). The samples were stirred and formed into handsheets on a Nobel and Wood 12-inch by l2-inch handsheet machine at the pH of local tap water (about 7.9). The handsheets were dried at 200250 F. The control containing no bentonite or diamine was not dyed. The sheet formed from a dispersion to which had been added 4 cc. of the clay dispersion was very slightly dyed. The sheets obtained using 1 and 2 cc.s of the diamine solution were lightly dyed. The sheets obtained using 4 cc. of the bentonite dispersion and either l or 2 cc.s of the diamine solution were dyed violet with the latter being somewhat more deeply colored. This unexpected improvement due to the use of the bentonite clay is also evident as the amount diamine used is increased although the degree of improvement is reduced.

EXAMPLE 11 Example I was essentially repeated except that the fatty diamine was replaced by a fatty monoamine of the formula R"-NH where R" is hydrogenated tallow (a mixture of saturated radicals consisting principally of straight chain 16 and 18 carbon atom alkyl from the corresponding fraction of acids obtained from tallow). The results were essentially the same as in example I with the control not being dyed, the sheet prepared using 4 cc. of the bentonite slurry being slightly dyed, the 1 cc. amine sheet being lightly dyed and the 4 cc. clay-l cc. amine sheet being dyed violet. A sheet prepared" using 4 CC. of the clay dispersion and 4 cc. of the amine solution was more intensely dyed than one using only 4 cc. of the amine solution.

EXAMPLE III A part of each of examples I and Il was repeated except that the handsheets were formed at an acid pH of about 4.8 to 5.6 (pH of dispersions adjusted by addition of H S0 The results are set forth in the following Table 1.

Parts of examples l and ll were repeated except that the dye solution was a 0.2 percent aqueous solution of the acid dye Calco Nigrosine O2P crystals. The following table 2 shows the additions and results;

TABLE 2 cc. of cc. of cc. of Bentonite Diamine Monoaminc Hnndshecl Dispersion Solution Solution Results I 0 0 0 Not dyed 2 2 t) 0 Not dyed "l 0 l 0 Lightly dycd 4 2 0 l Dycd cc. of cc. of cc. of Bcntonite Diumine Monoamine H 4 D' r Results 5 0 0 l Lightly dyed 6 2 O l Dyed EXAMPLE V A part of example ll was repeated except that the dye used was a 0.2 percent aqueous solution of the acid dye Calcocid Blue 26. Results are as follows:

A part of example ll was repeated except that the fatty monoamine was replaced by a quaternary compound of the formula: CHa

where R and R"" are mixed C C and C alkyl radicals as in the diamine of example I. The following Table sets forth the additions and results:

TABLE 4 cc. of cc. of Difatty Bentonite Quaternary Handsheet Dispersion Solution Results l 0 0 Not dyed 2 4 0 Slightly dyed 3 0 4 Dyed 4 4 4 lntensclydycd EXAMPLE Vll Example I was repeated except that the dye used was a 0.2 aqueous solution of Nigrosine O2P crystals and the diamine was replaced by a diamine of the formula H NCH D-CH NH where D is the divalent hydrocarbon radical derived as indicated above from the mixture of C acids prepared by polymerizing tall oil fatty acids. Table 5 recites the additions and results.

TABLE 5 cc. of cc. of Bentonite Diamine Huntlsheet Dispersion Solution Results 1 (l t) Not dyed 2 Z \I Not dye-l (l l Sltgltth dual 4 1 l 'iuhtly dyed hut appreciably more than 3 s o 2 Dyed 2 2 Dyed more intensely than 5 EXAMPLE VIII A part of example VI! was repeated except that diamine used therein was replaced by a fatty diamine of the formula tained from coconut oil). Table 6 sets forth the additions and results.

TABLE 6 cc. of cc. of Bcntonite Diamine Handsheet Dispersion Solution Results 5 l 0 0 Not dyed 2 2 0 Not dyed 3 0 1 Slightly dyed 4 2 I Dyed 2O EXAMPLE lX EXAMPLE X Example IX was essentially repeated except that the diamine was replaced by the quaternary used in example VI. The handsheets prepared from the dispersion containing both the clay and quaternary were deep blue in color being about twice as deeply dyed as those prepared from the dispersion containing no clay but only the quaternary. 0

EXAMPLE Xl Example IX was essentially repeated except that the dye used was Acid Violet and the diamine was replaced by the diamine used in example Vlll. The handsheets prepared from the dispersion containing both the clay and diamine werei much more deeply dyed than those prepared from the dispersions containing only the diamine or only the clay (in this instance as in example I, the clay alone did give very slight color retention). Improvement of less magnitude was also observed using other acid dyes-A20 Scarlet Y Orange Y and Scarlet BBA-in combination with the clay and the identified diamine.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The process of dyeing cellulosic fibers which comprises treating such fibers with (1) an aqueous solution of an anionic dye, (2) an alkali metal or acid montmorillonite clay and (3) a fatty nitrogen compound selected from those having the following formulas where p is an integer of l or 2, n is an integer of2 to about 4, m is an integer of 3 or 4, x is an integer of 2 to about 40, X is a quaternary ammonium anion, R is an aliphatic hydrocarbon radical of eight to 22 carbon atoms, R and R are hydrogen or aliphatic hydrocarbon radicals of eight to 22 carbon atoms, R is an alkyl group of one to about six carbon atoms or the benzyl radical or an aliphatic hydrocarbon substituted benzyl radical wherein the aliphatic substituent contains from one to about six carbon atoms, R and R are aliphatic hydrocarbon radicals of one to 22 carbon atoms, R is the polyvalent hydrocarbon radical of polymerized fat acids and D is the divalent hydrocarbon radical of dimerized fat acids, said polymerized and dimerized fat acids being derived from ethylenically unsaturated aliphatic monobasic carboxylic acids of 16 to 22 carbon atoms, and said montmorillonite clay and fatty nitrogen compound being used in an amount sufficient to increase the retention of the anionic dye by the fibers.

2. The process of claim 1 wherein the anionic dye is an acid dye.

3. The process of claim 2 wherein the montmorillonite clay and the fatty nitrogen compound are added to the fibers as aqueous dispersions or solutions.

4. The process of claim 3 wherein the montmorillonite clay is used in an amount of about 0.05 to 1.0 percent by weight .and the fatty nitrogen compound is used in an amount of about 0.05 to 1.0 percent by weight, said percents being based on the dry weight of the fibers.

5. The process of claim 4 wherein the clay is a sodium montmarillonite clay.

6. The process of claim 5 wherein the fatty nitrogen compound is an amine of the formula (1 7. The process of claim 6 wherein R and R are hydrogen and R is hydrogenated tallow.

8. The process of claim 5 wherein the fatty nitrogen compound is an amine of the formula (III).

9. The process of claim 8 wherein n is 2, R is D and D is the divalent hydrocarbon of a dimerized fat acid derived from a mixture of 18 carbon atom ethylenically unsaturated monobasic carboxylic acids rich in linoleic acid.

10. The process of claim 5 wherein the fatty nitrogen compound is a quaternary ammonium compound of the formula (V1).

11. The process of claim 10 wherein R and R are methyl and R and R are mixed l4, l6, and 18 carbon atom alkyl radicals.

12. In the process of preparing colored paper from an aq ueous dispersion of cellulosic fibers and an anionic dye, the improvement comprising adding an alkali metal or acid montmorillonite clay and fatty nitrogen compound to the dispersion before forming sheets from the dispersion, said clay and compound being used in an amount sufficient to increase the retention of the anionic dye by the cellulosic fibers and said fatty nitrogen compound having at least one aliphatic hydrocarbon radical of eight to 22 carbon atoms or at least one polyvalent hydrocarbon radical of a polymerized fat acid derived from ethylenically unsaturated aliphatic monobasic carboxylic acids of 16 to 22 carbon atoms.

13. The process of claim 11 wherein both the clay and fatty nitrogen compound are added to the fiber dispersion as dilute aqueous dispersions or solutions.

14. The process of claim 13 wherein the anionic dye is an acid dye, the clay is a sodium montmorillonite clay, the sodium montmorillonite clay and fatty nitrogen compound are used in amounts of about 0.05 to 1.0 percent by weight and about 0.05 to L0 percent by weight, respectively. the percents being based on the dry weight of the fibers, and the fatty nitrogen compound is selected from those having the formulas 12 (VIII) I R- onni-R I x;

where p is an integer of l or 2, n is an integer of 2 to about 4, m is an integer of 3 or 4, x is an integer of 2 to about 40, X is a quaternary ammonium anion, R' is an aliphatic hydrocarbon radical of eight to 22 carbon atoms, R and R are hydrogen or aliphatic hydrocarbon radicals of eight to 22 carbon atoms, R is an alkyl group of one to about six carbon atoms or the benzyl radical or an aliphatic hydrocarbon substituted benzyl radical where in the aliphatic substituent contains from one to about six carbon atoms, R and R are aliphatic hydrocarbon radicals of one to 22 carbon atoms, R is the polyvalent hydrocarbon radical of polymerized fat acids and D is the divalent hydrocarbon radical of dimerized fat acids, said polymerized and dimerized fat acids being derived from ethylenically unsaturated aliphatic monobasic carboxylic acids of 16 to 22 carbon atoms.

15. The process of claim 14 wherein the fatty nitrogen compound is an amine of the formula (1) where R and R are hydrogen and R is hydrogenated tallow.

16. The product prepared by the process of claim 1. 17. The paper product prepared by the process of claim 12. 

2. The process of claim 1 wherein the anionic dye is an acid dye.
 3. The process of claim 2 wherein the montmorillonite clay and the fatty nitrogen compound are added to the fibers as aqueous dispersions or solutions.
 4. The process of claim 3 wherein the montmorillonite clay is used in an amount of about 0.05 to 1.0 percent by weight and the fatty nitrogen compound is used in an amount of about 0.05 to 1.0 percent by weight, said percents being based on the dry weight of the fibers.
 5. The process of claim 4 wherein the clay is a sodium montmarillonite clay.
 6. The process of claim 5 wherein the fatty nitrogen compound is an amine of the formula (I).
 7. The process of claim 6 wherein R2 and R3 are hydrogen and R1 is hydrogenated tallow.
 8. The process of claim 5 wherein tHe fatty nitrogen compound is an amine of the formula (III).
 9. The process of claim 8 wherein n is 2, R is D and D is the divalent hydrocarbon of a dimerized fat acid derived from a mixture of 18 carbon atom ethylenically unsaturated monobasic carboxylic acids rich in linoleic acid.
 10. The process of claim 5 wherein the fatty nitrogen compound is a quaternary ammonium compound of the formula (VI).
 11. The process of claim 10 wherein R4 and R6 are methyl and R1 and R5 are mixed 14, 16, and 18 carbon atom alkyl radicals.
 12. In the process of preparing colored paper from an aqueous dispersion of cellulosic fibers and an anionic dye, the improvement comprising adding an alkali metal or acid montmorillonite clay and a fatty nitrogen compound to the dispersion before forming sheets from the dispersion, said clay and compound being used in an amount sufficient to increase the retention of the anionic dye by the cellulosic fibers and said fatty nitrogen compound having at least one aliphatic hydrocarbon radical of eight to 22 carbon atoms or at least one polyvalent hydrocarbon radical of a polymerized fat acid derived from ethylenically unsaturated aliphatic monobasic carboxylic acids of 16 to 22 carbon atoms.
 13. The process of claim 11 wherein both the clay and fatty nitrogen compound are added to the fiber dispersion as dilute aqueous dispersions or solutions.
 14. The process of claim 13 wherein the anionic dye is an acid dye, the clay is a sodium montmorillonite clay, the sodium montmorillonite clay and fatty nitrogen compound are used in amounts of about 0.05 to 1.0 percent by weight and about 0.05 to 1.0 percent by weight, respectively, the percents being based on the dry weight of the fibers, and the fatty nitrogen compound is selected from those having the formulas:
 15. The process of claim 14 wherein the fatty nitrogen compound is an amine of the formula (I) where R2 and R3 are hydrogen and R1 is hydrogenated tallow.
 16. The product prepared by the process of claim
 1. 17. The paper product prepared by the process of claim
 12. 